The present invention is directed to a connecting device for flexible electrical connection of circuit boards.
A connecting device is described in U.S. Pat. No. 3,601,755, in which a plurality of wires positioned adjacent to each other are embedded in an insulation. The wires are flattened in the area of the insulation, while outside of the insulation the round shape of the wires is preserved. The round ends of the wires can be inserted into contact holes of a circuit board. The installation of such a conductor is typically performed by hand.
The connecting device according to the present invention has the advantage over the related art that the connecting device, having a plurality of conductors embedded in an insulation, is formed in such a way that the connecting device may be picked up in an advantageous manner by a tool, and the ends of the electrical conductors may be inserted into contact openings of a circuit board by machine. The electrical conductors have in their end areas a first and a second contact area without insulation. The electrical conductors and the insulation are plastically deformable, so that impressed shapes are advantageously retained. Thus the electrical conductors and the insulation are shaped advantageously into a shoulder in an area adjoining the first and second contact areas, thereby offering the possibility that the connecting device may be picked up by a tool. In order to also enable insertion of the connecting element into a circuit board by machine, the ends of the electrical conductors are directed to the same side in the first and second contact areas in the direction of a circuit board.
Advantageously, the insulation has an elongated opening between each pair of electrical conductors. This removal of material increases the flexibility of the connecting device and reduces the transmission of vibrations through the connecting device.
Advantageously, the electrical conductors are of flat design in the area of the insulation and of round design in the contact areas. This enables the round ends of the electrical conductor to be guided easily into contact openings of circuit boards, and the flat area of the electrical conductor can easily be plastically deformed along the course of the conductor, and is dimensionally stable against forces that act at right angles to the plane of the flat conductor.
By preference, the electrical conductor is made of tin-plated copper. Copper not only contributes to good electrical conductivity, but is also readily shaped. The tin-plated surface protects the copper against corrosion, and provides a readily solderable surface.
Advantageously, the electrical conductors and the insulation are shaped as a loop between the first and the second contact areas. This configuration makes it possible for forces that act on one contact area of the connecting device due to vibrations of the circuit board to be damped over the length of the loop, so that only small forces are transmitted to the other contact area.
Advantageously, the connecting device is installed using a tool according to the present invention. The shoulders of the connecting device are grasped in an advantageous manner from below and from the side by a gripper, while a plunger presses the shoulder against the gripper from above.
Thus, using this tool, the connecting device may be picked up and inserted in an advantageous manner by machine and automatically.